In many respects, the U.S. national team has to be wondering which Panama side will show up when the two square off in a World Cup qualifying match on Wednesday night in Panama City.

Will the gritty side that had Bruce Arena's team on the ropes in front of their home crowd during the 1-1 tie on September 8 show up? Or will it be the group that received a 6-0 shellacking at RFK Stadium on October 13?

It's hard to tell. Without a doubt, playing at home will be a factor and provide a huge lift for the Panamanians. Yet, it'll be an entirely different situation altogether on Wednesday night than it was nine months ago.

When the two teams squared off in Estadio Rommel Fernandez last fall, Panama was coming off the biggest victory in the history of its soccer program. Just four days earlier, the "Reds" shocked the Jamaican side in a 2-1 upset on the road. It created a buzz in Panama City going into the encounter with the U.S. since the team was now tied for second in the group standings and had a realistic shot at making it out of the group and into the final round of CONCACAF qualifying for the first time ever.

That's why it was no surprise to see Panama ride a wave of energy throughout that match and nearly pull off what would have been a monumental upset had Cobi Jones not slid in a water-logged ball into the back of the net in stoppage time to give the U.S. a point on the road.

This time around, the Americans storm into town with a 3-1 record, coming off an impressive 3-0 victory over Costa Rica on Saturday. They stand just a point behind Mexico in the group standings and are looking to nearly clinch a berth into the World Cip with a victory on the road come Wednesday night.

Panama, on the other hand, is practically limping into this match, as the 2-0 loss to Trinidad & Tobago knocked them down into last place in the group with a 0-2-2 record. It also didn't help that a cancelled flight held the team up some 36 hours before it arrived back home. The momentum that was once there after making it into the final six of the CONCACAF region is gone. It's one of the reasons that the U.S. will likely play in more of a straight-up fashion than lie back and hope to escape with a tie.

That isn't to say that the Canaleros won't be dangerous, though. Despite getting manhandled at RFK last October, there are several players on the side that are a handful. Flank midfielder Ricardo Phillips is Panama's version of Manchester City and England national team midfielder Shaun Wright-Phillips. The diminutive Panama speedster gave the U.S. fits in the 1-1 tie. Since Greg Vanney struggled so mightily against him that night, it'll make it difficult for Arena to put him out there as the left back.

Up top, Roberto Brown will also be a player the U.S. is watching from the start, as the powerful striker not only scored Panama's lone goal at home last time around, but he also won several balls for his side and made U.S. defender Eddie Pope work extremely hard throughout the night. Where he struggles is in his run-making and ability to get pulled offsides. If Pope pulls his line up the way he did against Costa Rica, Brown will surely be caught more than a few times.

Probably the most dangerous player for Panama will be Julio Medina. The creative midfielder likes to roam up to the left flank, but he'll also run the break from the center of the field. Medina has great vision and is unafraid to take chances, whether it's taking a shot from 35 yards out or by running at defenders.

Defensively, Panama's best player is Luis Moreno, who can play either as a center-back or on the right, but he'll be out due to yellow card accumulation. By and large, this is the weakest part of the side, which was obviously seen in the 6-0 loss in October. Unfortunately for the U.S., Eddie Johnson (turf toe) will not be available for the match. It was his hat trick that stunned the Reds in that aforementioned match. With Panama likely to attack with a vengeance since a victory is needed to stay alive, having Johnson and his speed up top would have been key for Arena and his side.

Instead, Arena will likely go with a partnership of Brian McBride and Josh Wolff up top. This duo played together in the 2-1 loss England on May 28th, and were two of the three forwards against Costa Rica over the weekend.

In the midfield, Arena's options continue to be limited since Claudio Reyna, Eddie Lewis and Pablo Mastroeni are all unavailable. There's a chance that a box-like midfield shape could be utilized as it has in the past, perhaps using Kerry Zavagnin and Clint Dempsey as holding midfielders with DaMarcus Beasley and Landon Donovan in front of them as attackers. Since the field at Estadio Rommel Fernandez is not very wide -- it looks like an average high school field in the U.S. -- that could be a smart option. If that's not the case, there's a good possibility that Steve Ralston gets yet another start -- it would be his fourth in a row for the national team -- out on the right flank, to go along with Beasley on the left, Donovan at the top of the diamond and Zavagnin in the holding role.

Not all of Arena's options in the back are available, as well, considering that he had to leave defender Cory Gibbs Cory Gibbs back in the U.S. due to a bruised knee. That, combined with the fact that Oguchi Onyewu is also nursing a knee injury, could mean the return of Gregg Berhalter to the lineup to pair with Pope as centerbacks. Those two played as a duo against Panama in the 6-0 win at RFK. If that happens, Carlos Bocanegra would play out on the left and either Frankie Hejduk and Steve Cherundolo on the right.

Since Cherundolo is coming off of a few impressive performances, it wouldn't be a shock to see him get the nod on the right, and move Hejduk to the left to try and neutralize the speed of Phillips. If that's the case, Pope and Bocanegra would be the pairing in the central defense, just as they were in the first match against Panama last September.

The easiest decision for Arena, once again, is to go with Kasey Keller in the goal. The 35-year-old is coming off one of his best performances in a U.S. jersey, positing a clean sheet against Costa Rica due to three acrobatic saves on excellent bids by the Ticos.

Keller might have to face several hard shots from Philips and Medina, as he did last September. Or he could have a relatively quiet evening like he did in the return match at home in October.

It all depends which Panama team decides to show up.

Marc Connolly covers soccer for ESPN.com. He can be reached at: marc@oakwoodsoccer.com.